Method for manufacturing laminate of material layers, method for manufacturing electrode for solid-state battery, material layer, and method for manufacturing material layer

Abstract

To provide a method for manufacturing a laminate with a smaller proportion of a substrate relative to a total volume of the laminate.SOLUTION: A method for manufacturing a laminate of material layers, the method comprising: a step of arranging a plurality of particles on an adhesion surface of a first substrate having the adhesion surface; a step of filling a binder releasable from the adhesion surface between the plurality of particles arranged on the adhesion surface to obtain a material layer that is an integral structure of the particles and the binder; and a step of peeling the material layer from the adhesion surface, stacking the plurality of material layers, and obtaining a laminate of the material layers.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a material layer and an electrode for a solid-state battery, and a material layer. [Background technology]

[0002] In recent years, various new manufacturing methods using additive manufacturing technologies have been developed. However, the technology for designing and arranging multiple material particles to create functional structures remains difficult and has not been widely implemented. For example, while the technology for arranging toner particles using electrophotography is widely used, toner particles are made of composite materials that already contain several times the amount of binder as the functional material pigment in order to obtain charging properties. Furthermore, due to the properties of electrostatic charges, positioning individual particles is fundamentally difficult. This phenomenon also applies to electrostatic screen printing, which can pattern particles without binders. If functional particles can be placed in the right places, unnecessary particles can be avoided, and greater effects can be achieved, for example, with expensive materials such as battery materials.

[0003] Conventionally, Patent Document 1 discloses a technology for manufacturing a solid-state battery in which particles arranged on a substrate are stacked together with the substrate in multiple layers to obtain a laminate, thereby manufacturing a solid-state battery with a larger capacity. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-137060 Summary of the Invention [Problem to be solved by the invention]

[0005] The substrate in the laminate produced by the method of Patent Document 1 is removed because it contributes little to the characteristics of the solid-state battery. Therefore, it is desirable that the ratio of the substrate to the total volume of the laminate be small. However, because the substrate also serves as a support for the particles, it has been difficult to make the substrate thinner than a certain level.

[0006] The present disclosure provides a method for manufacturing a laminate in which the proportion of the substrate in the total volume of the laminate is smaller. The present disclosure also provides a method for manufacturing an electrode for a solid-state battery using the laminate. The present disclosure also provides a material layer in which the proportion of the substrate is smaller. The present disclosure also provides a method for manufacturing a material layer in which the proportion of the substrate is smaller. [Means for solving the problem]

[0007] The present disclosure provides a method for manufacturing a stack of material layers, comprising: The manufacturing method includes: disposing a plurality of particles on an attachment surface of a first substrate having the attachment surface; a step of filling a binder releasable from the attachment surface between the plurality of particles arranged on the attachment surface to obtain a material layer that is an integral body of the particles and the binder; peeling the material layer from the attachment surface to stack a plurality of the material layers to obtain a stack of the material layers; The present invention relates to a method for manufacturing a stack of material layers, having the following structure:

[0008] The present disclosure also provides a method for manufacturing an electrode for a solid-state battery, comprising: The manufacturing method comprises: The present invention relates to a method for manufacturing an electrode for a solid-state battery, comprising a step of heating and degreasing the laminate obtained by the method for manufacturing a laminate of material layers to remove the binder and obtain the electrode.

[0009] The present disclosure also provides a material layer that is an integral body of a plurality of particles and a binder, comprising: the binder is filled between the particles, At least a portion of the particles is exposed from the binder on at least one surface of the material layer; The present invention relates to a material layer in which, when the material layer is observed from the side where at least a portion of the plurality of particles is exposed, the ratio of the total area of ​​the exposed portions of the particles to the area of ​​the particle arrangement area where the plurality of particles are present is 1 to 70 area %.

[0010] The present disclosure also provides a method for manufacturing a layer of material, comprising: The manufacturing method includes: disposing a plurality of particles on an attachment surface of a first substrate having the attachment surface; a step of filling a binder releasable from the attachment surface between the plurality of particles arranged on the attachment surface to obtain a material layer that is an integral body of the particles and the binder; peeling the layer of material from the attachment surface; The present invention relates to a method for manufacturing a material layer having the following features. [Effects of the Invention]

[0011] According to the present disclosure, there is provided a method for manufacturing a laminate in which the proportion of the substrate in the total volume of the laminate is smaller. Also according to the present disclosure, there is provided a method for manufacturing an electrode for a solid-state battery using the laminate. Also according to the present disclosure, there is provided a material layer in which the proportion of the substrate is smaller. Also according to the present disclosure, there is provided a method for manufacturing a material layer in which the proportion of the substrate is smaller. [Brief explanation of the drawings]

[0012] [Figure 1] Image showing the manufacturing method of the material layer [Figure 2] An explanatory diagram illustrating a manufacturing process for a laminate of material layers. [Figure 3] Schematic diagram of an apparatus for producing a stack of material layers [Figure 4] Air knife coater illustration [Figure 5] Explanatory diagram of a laminate [Figure 6] Schematic of material layers [Figure 7] Illustration of a secondary electron image of a material layer DETAILED DESCRIPTION OF THE INVENTION

[0013] In the present disclosure, expressions such as "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the endpoints, that is, the lower and upper limits, unless otherwise specified. Furthermore, when a numerical range is described in stages, the upper and lower limits of each numerical range can be arbitrarily combined. Furthermore, in the present disclosure, expressions such as "at least one selected from the group consisting of XX, YY, and ZZ" mean any of XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, or a combination of XX, YY, and ZZ. Furthermore, when XX is a group, multiple XXs may be selected, and the same applies to YY and ZZ.

[0014] In the present disclosure, a layer of material particles is completed on a first substrate as an intermediate transfer member, and then a binder that will become the final substrate is infiltrated between the particles to obtain a material layer that is an integrated particle-binder structure. The material layers are then stacked to obtain a laminate, thereby reducing the amount of binder (substrate amount), which is an unnecessary component in the target laminate. Therefore, when removing the substrate, removal is facilitated. For example, when removing the substrate by heating, the heating temperature can be lowered and the heating time can be shortened.

[0015] It is also possible to form a pattern using material particles, in which case the accuracy of the pattern can be maintained by holding the particles on an intermediate transfer body until a unit of the particles containing the pattern and the binder is obtained.

[0016] Specifically, for example, particles are temporarily fixed as a pattern on a weakly adhesive surface with elastic deformation, such as silicone rubber, without using a fixing material. Then, a treatment liquid containing a binder is allowed to penetrate into the gaps in the particle pattern, and after removing the solvent, the particles are transferred to the transfer target and laminated. This method allows the particles to be fixed with a small amount of binder depending on the particle size used, and also allows the use of a binder material that is easy to remove.

[0017] Hereinafter, an embodiment of the present disclosure will be illustrated step by step. FIG. 1 is a flow chart of a method for manufacturing a particle-containing material layer. FIG. 2 shows a specific example of a manufacturing process for a stack of material layers in order of steps.

[0018] The method for manufacturing a stack of material layers comprises: disposing a plurality of particles on an attachment surface of a first substrate having the attachment surface; a step of filling a binder releasable from the attachment surface between the plurality of particles arranged on the attachment surface to obtain a material layer that is an integral body of the particles and the binder; peeling the material layer from the attachment surface to stack a plurality of the material layers to obtain a stack of the material layers; It has.

[0019] The particles are preferably patterned. There are no limitations on the method for forming a particle pattern on the attachment surface. Since the particles are held together by the adhesive force at the interface between the attachment surface serving as an intermediate transfer member and the particles, the particles are basically held together at a thickness equivalent to a single layer of particles regardless of the patterning method used. The method can be suitably selected depending on the particles used, whether it is a plate-based method such as relief printing or intaglio printing, or a plateless method such as electrophotography. Among these, a patterning method using a mask is preferred.

[0020] Hereinafter, an example of arranging first particles and second particles using a mask will be described, but the plurality of particles is not limited to this form. The plurality of particles may be particles of one type. Here, the type may be, for example, a type of compound. For example, the plurality of particles may include a plurality of particles of the same compound. Furthermore, the plurality of particles may include a first particle, a second particle, a third particle, ... an n-th particle. For example, the plurality of particles may be arranged using a plurality of masks.

[0021] The process of arranging a plurality of particles on the adhesion surface preferably includes a first process of forming a mask on the adhesion surface, a second process of arranging first particles in areas of the adhesion surface where the mask is not formed, a third process of removing the mask from the adhesion surface, and a fourth process of arranging second particles in areas where the first particles remaining on the adhesion surface are not arranged.

[0022] Alternatively, the plurality of particles may be arranged without using a mask. For example, the step of arranging the plurality of particles on the attachment surface may be a step of arranging the first particle on the attachment surface.

[0023] 2A to 2G show a specific example of the process of the present disclosure in order of steps. First, a first substrate 20 (intermediate transfer member) having a particle-carrying layer 29 forming an attachment surface 21 on the surface of a support 101 is prepared (FIG. 2A). A mask 22 having openings 23 is formed on the attachment surface 21 of the first substrate 20 (FIG. 2B). There are no particular restrictions on the formation of the mask 22, and known means can be used. For example, a mask layer is separately formed on a support member, and the desired openings 23 are formed on the mask 22. 3, and then transfer the mask 22 from the support member to the attachment surface 21.

[0024] Then, first particles 24 are placed in openings 23, which are portions of attachment surface 21 where mask 22 is not formed (FIG. 2C). This allows first particles 24 to adhere to attachment surface 21. Next, mask 22 is removed from attachment surface 21 (FIG. 2D). By removing the mask, new areas on the attachment surface where the first particles are not placed are exposed. Second particles 25 are then placed in the exposed areas where the first particles are not placed (FIG. 2E). This allows the second particles 25 to be attached to the attachment surface 21, completing the pattern of the first particles and second particles.

[0025] A binder 27 that can be peeled off from the adhesion surface is filled between the particles in this pattern of first and second particles to obtain a material layer that is an integrated body of the particles and the binder. For example, a binder solution containing the binder is allowed to penetrate between the particles, and then the solution is dried to obtain a material layer that is an integrated body of the particles and the binder (FIG. 2F). The resulting material layer can then be peeled off from the attachment surface 21 (FIG. 2G). The resulting material layers can be stacked to obtain a laminate (FIG. 5A).

[0026] 3 shows an example of an apparatus 100 for producing a material layer and a material layer laminate according to one embodiment of the present disclosure. The apparatus is an apparatus for producing, for example, a positive electrode material layer and further a positive electrode material layer laminate.

[0027] Using the apparatus shown in FIG. 3, for example, a PET film mask with openings formed by a UV laser 6 is attached to an intermediate transfer body 1 having a silicone rubber surface. Then, particles of a battery cathode material are supplied by a first particle supply unit 7, and after the mask is peeled off, particles of a battery solid electrolyte are supplied by a second particle supply unit 11. Furthermore, a treatment liquid containing an acrylic binder is supplied to gaps between the particle layers on the intermediate transfer body 1 by an air knife coater 13, allowed to penetrate, and then the solvent is removed to produce a cathode material layer. These material layers are then laminated in a lamination device 15 to produce a laminate of cathode material layers. The production apparatus 100 will now be described.

[0028] The production apparatus 100 is equipped with a belt-like intermediate transfer body 1, a transport device that transports the intermediate transfer body between processes, and processing means for carrying out the processes shown in Fig. 2. The intermediate transfer body 1 is the first substrate 20 having the above-mentioned attachment surface 21.

[0029] The manufacturing apparatus 100 is centered around a conveying device 2 that drives the intermediate transfer body 1, and includes a mask layer attachment unit that includes a mask layer supply section 30 that supplies a mask layer 3 and a pressure roller 4, a mask manufacturing unit 6 (UV laser 6), a cleaning roller 5, a first particle supply unit 7, and an air blower 8. The manufacturing apparatus 100 also includes a mask removing unit that is composed of a peeling roller 9 and a winding device 10. The manufacturing apparatus 100 also includes a second particle supplying unit 11 and an air blower 12.

[0030] The manufacturing apparatus 100 also includes an air knife coater 13 as a means for applying a treatment liquid containing a binder to fill the particles with the binder, and a solvent removal promoting means 14 for removing the solvent after applying the treatment liquid. The manufacturing apparatus 100 also includes a lamination device 15 for laminating material layers, in which a binder is heated by a heater 16 to laminate the material layers, and the binder is cooled by a cooling fan 17 to make it easier to peel the material layers from the intermediate transfer body.

[0031] These units are processed sequentially to produce layers of material. The apparatus shown in FIG. 3 has a configuration in which each step is performed in a series, but this is not limiting. The following description will be given using the device in FIG. 3 as an example.

[0032] First, the intermediate transfer member must have the property of being able to transfer target particles to the final substrate while retaining them on its surface. To achieve this, the intermediate transfer member 1 has an attachment surface 21. The outer surface of the intermediate transfer member 1 serves as the attachment surface 21. For example, the intermediate transfer member 1 has a particle-carrying layer 29 having the attachment surface 21. That is, the first substrate preferably has a support 101 and a particle-carrying layer 29 laminated on the support 101 to form the attachment surface 21.

[0033] The intermediate transfer body 1, which is the first substrate, temporarily holds the particles and ultimately releases them (i.e., transfers them to the desired transfer target), so the particle-carrying layer needs to have properties that allow the particles to be released. A suitable property is, for example, that the particle-carrying layer 29 is an elastically deformable layer. If the particle-carrying layer 29 is rigid, the contact points with the particles tend to be small point contacts, which requires a strong adhesive force, which can result in incomplete release of the particles or damage to parts of the particles or the surface of the intermediate transfer body.

[0034] In this regard, if the particle-carrying layer 29 is elastically deformable, some of the particle contact points will sink into the transfer body, increasing the contact area and allowing the particles to be reliably held with weak adhesive force, allowing for stable peeling of the material layer. If the adhesive layer is made of a plastically deformable material, the particles will be held in a buried state, making peeling difficult. The amount of particle sinking can be controlled by the rubber hardness of the intermediate transfer body surface.

[0035] In addition, as another characteristic that stabilizes peeling (transferability) from the intermediate transfer body, it is desirable that the adhesion surface 21 have low compatibility (adhesion and solubility) with the treatment liquid containing a binder. Therefore, the particle support layer 29 having the adhesion surface 21 should be selected based on its compatibility with the treatment liquid, particularly the solvent of the treatment liquid. A specific material for the particle support layer 29 that satisfies these requirements is urethane rubber for aqueous treatment liquids. Furthermore, fluororubber and silicone rubber can be used with a wide range of materials, regardless of whether they are aqueous or solvent-based. Silicone rubber is particularly suitable because it has a wide range of adjustable adhesiveness and rubber hardness. The particle support layer 29 does not need to be made of a single rubber; multiple types can be used in combination depending on the properties.

[0036] For example, the adhesive strength of the adhesion surface 21 measured by a peel analysis device is preferably 0.2 to 10 mN / 20 mm, more preferably 0.4 to 5 mN / 20 mm, even more preferably 0.5 to 5 mN / 20 mm, and even more preferably 0.5 to 2 mN / 20 mm. The adhesive strength was measured using a VPA-3 manufactured by Kyowa Interface Science Co., Ltd. under the following measurement conditions. In the examples described later, the sample size was 20 mm wide and 150 mm long. Measurement conditions: peel angle 90°, measurement temperature 25°C, peel speed 300 mm / min, target substrate: PET film From the viewpoint of sufficiently holding the particles, the adhesive force is preferably 0.2 mN / 20 mm or more, and from the viewpoint of better transferability, the adhesive force is preferably 10 mN / 20 mm or less.

[0037] Furthermore, as elastic properties, the rubber hardness of the attachment surface 21 measured in accordance with JIS K6253-3:2012 is preferably 10° to 80° (JIS type A), more preferably 15° to 40°, even more preferably 18° to 40°, and even more preferably 18° to 30°. The rubber hardness in this disclosure refers to a durometer hardness that can be measured in accordance with JIS K6253-3:2012. The thickness of the particle-supported layer 29 is, for example, 10 to 200 μm, preferably 40 to 120 μm.

[0038] Specifically, the material of the particle carrying layer 29 that forms the adhesion surface 21 is silicone rubber, urethane, or the like. Preferably, the particle support layer 29 contains rubber or fluororubber. Alternatively, it may be a mixture of any of these with other materials. The particle support layer 29 contains, for example, at least one selected from the group consisting of silicone rubber, urethane rubber, and fluororubber, more preferably silicone rubber, and even more preferably silicone rubber. The particle support layer 29 preferably contains 10 to 100% by mass, more preferably 50 to 100% by mass, and even more preferably 80 to 100% by mass of at least one selected from the group consisting of silicone rubber, urethane rubber, and fluororubber. The particle support layer 29 preferably contains 10 to 100% by mass, more preferably 50 to 100% by mass, and even more preferably 80 to 100% by mass of silicone rubber.

[0039] The solubility of the particle-carrying layer that forms the adhesive surface with the binder liquid preferably satisfies the following: When the particle-carrying layer is immersed in the binder liquid for 1 hour in a 25°C environment, the reduction in the particle-carrying layer is preferably 0 to 5% by mass, and more preferably 0 to 1% by mass. The above temperature simulates the process temperature. Satisfying the above mass reduction rate indicates that the binder liquid and the adhesive surface are less compatible, which tends to result in better transferability.

[0040] In the device 100 of FIG. 3, the intermediate transfer body 1 is in the form of a belt, but is not limited to this. For example, the intermediate transfer body 1 may be in the form of a roller or a flat plate. The support of the intermediate transfer body 1 is not limited, and commercially available materials can be used depending on the application. Examples include plastics such as polyamide resin, polyimide resin, polyacetal resin, and polyester resin, metals such as aluminum, stainless steel (SUS), and Invar alloy, as well as glass and ceramics in the form of a roll or flat plate.

[0041] Since the particle-carrying layer 29 is easily stretched and contracted when used alone, and the dimensional accuracy may be unstable, it is preferable to use a rigid body for the support. In the apparatus 100 shown in Fig. 3, the lamination device 15 uses a heat-pressing method, and therefore uses Invar material, which has high thermal conductivity and dimensional stability. When the first substrate as the intermediate transfer member 1 is in the form of a belt, the thickness of the support may be, for example, 0.01 to 1.0 mm, or 0.05 to 0.5 mm.

[0042] There are no limitations on the method for forming the particle pattern on the intermediate transfer body. General patterning techniques can be applied. In the device shown in Figure 3, a 1.5 μm thick polyester film is placed on a glass pressure roller, and a mask with openings made by a UV laser is attached to the intermediate transfer body using the pressure roller. The surface of the intermediate transfer body, the attachment surface 21, has adhesive strength in a peelable state, so this can be used to hold the mask in place.

[0043] Battery cathode material particles are applied as first particles to the non-formation areas of the mask, and when the mask film is peeled off, the particles adhere only to the mask openings, creating a pattern. Next, solid electrolyte particles are applied as second particles to the non-arrangement areas of the first particles remaining on the attachment surface 21, and the second particles selectively adhere to the areas where the first particles are not attached, i.e., the exposed areas of the attachment surface, completing a pattern using two particle materials.

[0044] Therefore, the method for manufacturing a stack of material layers includes a first step of forming a mask on the attachment surface 21. The means for forming the mask is not particularly limited, and may include, for example, a step of providing a mask layer 3 on the attachment surface 21 and a step of forming an opening 23 in the mask layer 3 to form a mask 22.

[0045] The apparatus in FIG. 3 includes, for example, a supply means for supplying the mask layer 3, a UV laser 6 as a means for forming openings 23 in the mask layer 3, and a pressure roller 4 as a means for attaching the mask 22 onto the attachment surface.

[0046] There are no restrictions on the material of the mask layer 3, but a material that is uniform in thickness and easy to process is suitable. For example, plastics such as polyimide resin, polyacetal resin, and polyester resin, and metal foils such as aluminum, stainless steel (SUS), and invar alloy are available in high quality on the market, so these are suitable for use. Plastics are preferred.

[0047] The thickness of the mask is preferably selected to be equal to or less than the diameter of the particle material used. The arrangement of the first particles is not limited to a thin film equivalent to a particle monolayer, but is particularly suitable for forming a thin film equivalent to a particle monolayer. That is, the thickness of the arranged first particles is, for example, 0.80 to 1.20 times, or 0.90 to 1.10 times the volume-based median diameter D50 of the first particles. The arranged first particles are preferably approximately a monolayer. This is because, in principle, the degree of freedom in particle pattern arrangement is greatest when a laminate is made by stacking two-dimensionally patterned sheets with a thickness equivalent to a particle monolayer.

[0048] Within this range, the thicker the mask, the greater its durability, making it easier to handle and increasing the number of times it can be reused. This is suitable for cases where there are few pattern changes or when producing large quantities. On the other hand, the thinner the mask, the less material is required, making it suitable for cases where there are many pattern changes or when producing small quantities. The thickness of the mask is preferably 0.05 to 1.10 times, more preferably 0.20 to 1.00 times, and even more preferably 0.20 to 0.50 times the volume-based median diameter D50 of the first particles. Examples of the thickness of the mask layer include 0.5 to 100 μm, 1 to 50 μm, and 1 to 5 μm.

[0049] The thickness of the mask is also preferably in the range of not less than the cumulative 10% particle size (D10) in the particle size distribution on a volume basis of the first particles and not more than the cumulative 90% particle size (D90) in the particle size distribution on a volume basis of the first particles. The volume-based median particle diameter D50 is the cumulative 50% particle diameter (median diameter: D50) in the particle size distribution on a volume basis. The particle diameter was measured using a laser diffraction / scattering particle size distribution analyzer (LA-960, manufactured by Horiba, Ltd.).

[0050] There are no limitations on the formation of the openings, and it is desirable to select an appropriate method based on the mask layer material and the resolution of the design pattern. If few pattern changes are required and high resolution is desired, etching metal foil using photolithography is suitable, while if relatively low resolution is sufficient, creating openings in a resin film using a thermal head is suitable. The material layer production device 100 in Figure 3 is equipped with a UV laser 6.

[0051] The shape of the mask portion is not particularly limited, but can be, for example, a stripe or honeycomb shape. When the mask portion is stripe-shaped, the width of the opening is not particularly limited, but can be 1 to 200 μm or 2 to 100 μm. The width of the mask portion can be 1 to 200 μm or 2 to 100 μm.

[0052] The mask openings 23 may be formed with the mask attached to the intermediate transfer body 1, but from the viewpoint of protecting the surface of the particle-carrying layer from contamination and damage, it is preferable to form a mask layer 3 separately on a support member, form the openings, and then transfer it to the intermediate transfer body.

[0053] For example, a material with a lower absorption rate for the laser used than the mask layer is suitable for the support member used to form the opening. Specifically, glass is preferable to a thin plastic mask. Plastic has a higher absorption rate for CO2 lasers and UV lasers than glass. Glass is also suitable because it is a material that can easily create a high level of surface smoothness.

[0054] The manufacturing apparatus 100 shown in Figure 3 uses a pressure roller 4 as a support member. The pressure roller 4 can be, for example, a glass cylinder. The support member can be a flat plate, or it can be rolled up if flexible materials such as polyimide film or SUS foil are used. The technology for processing glass cylinders with high precision is commonplace and is currently produced and utilized in a wide range of industries, making them easy to obtain. In the case of laser processing, the focal length has a significant effect on accuracy, so a high-precision glass cylinder is also preferred. The mask layer 3 transported on the pressure roller can be drilled to form openings 23.

[0055] In the manufacturing apparatus 100 shown in FIG. 3, a polyester film, which is a material for the mask layer 3 and is wound in a roll, is fed by a pressure roller 4 while being irradiated with a laser 6 according to a design pattern, thereby performing hole drilling. The masks are then continuously attached to the intermediate transfer body 1, and the subsequent steps from the particle supplying step to the mask peeling step are carried out in a consistent manner, but the present invention is not limited to this.

[0056] For example, a configuration for batch processing of sheet-like film is also possible. The advantage of using a roller-shaped substrate for creating apertures is that it allows for easier handling during mask transfer because it can utilize the curvature. If the pressure roller is a rigid body such as glass, it may seem unsuitable for attaching a thin film mask to the surface of the intermediate transfer body 1, but if the particle-carrying layer on the surface of the intermediate transfer body 1 is elastic, then attachment pressure can be applied without any problems.

[0057] The device shown in Figure 3 uses one mask to pattern two material particles, but by using multiple masks, it is possible to create patterns of three or more types of materials.

[0058] Following the first step, a second step is carried out in which first particles are placed in the non-mask-forming areas of the attachment surface 21. That is, a mask with openings is placed on the intermediate transfer body 1, and then the first particles are placed. There are no particular restrictions on the particles used and the method for supplying the particles, and a wide range of known methods can be applied. Specifically, the particles can be sprinkled by gravity and spread by vibration, attached by spraying, or supplied using a roller, brush, or blade. If it is desired to densely fill the mask openings with particles, it is preferable to apply a rubbing force.

[0059] Among these, rubbing using magnetic particles is preferred when a mask is used. That is, the first particles are preferably arranged by using magnetic particles as a carrier material to support the first particles and then rubbing the first particles against the attachment surface 21. The first particles can be supported by forming a magnetic brush using magnetic particles as a carrier material. The rubbing force can be easily changed depending on the particle by controlling the magnetic force. Using large magnetic particles is a good match, as the particles can be filled while pressing the mask against the transfer body. The first particles may be a single material or a premix of multiple particles. Of course, the particle surface may be subjected to a surface treatment or coating.

[0060] The apparatus 100 in Figure 3 has a cleaning roller 5 as a means for cleaning the surface of the mask layer 3 and ensuring that it adheres securely to the attachment surface 21. This acts to remove static electricity and ablation residues that may adhere during laser processing. This may not be necessary if the pattern is rough, but it is effective for fine patterns.

[0061] In the apparatus 100 of FIG. 3, the first particle supply unit 7 operates a backside magnet to rub magnetic particles carrying material particles on the surface of the patterning area, thereby increasing the particle density. Also, after the second step of disposing the first particles in the non-forming areas of the mask, an excess particle removal step of removing excess particles may be performed. In the apparatus 100 of FIG. 3, after the pattern is completed, a monolayer of particles is formed. An air blower 8 is provided as an excess particle removal means for facilitating the removal of the particles deposited in two layers on top.

[0062] The particles are held to the intermediate transfer body by adhesive force at the interface, so that in principle they are held at a thickness equivalent to a single layer of particles, regardless of the patterning method used.

[0063] The method for manufacturing a material layer includes a third step of removing the mask from the deposition surface. The means for removing the mask is not particularly limited, and any known means may be used. For example, the mask may be peeled off. As a mechanism for peeling the mask from the first substrate, the apparatus shown in FIG. 3 uses a peeling roller 9 and a winding device 10 to wind up the mask in the form of a continuous film.

[0064] Next, a fourth step is performed in which second particles are placed in the non-placed areas of the first particles remaining on the attachment surface. That is, the second particles are placed in the mask-removed areas. The particle-carrying layer of the intermediate transfer body that was protected by the mask is now exposed, so the second particles selectively adhere to this area. The second particles may be the same as the first particles, or different from the first particles.

[0065] As with the arrangement of the first particles, the supply method is not limited and can be selected according to the particles to be used. In FIG. The second particle supply unit 11 may be the same as the first particle supply unit 7. After the second particles are supplied, excess particles may be removed in the same manner as after the placement of the first particles. For example, in FIG. 3, the manufacturing apparatus 100 includes an air blower 12.

[0066] In the device shown in Figure 3, a pattern consisting of two types of particles was formed using one mask, but this is not limited to this. For example, if two masks are used, offset from one another, a pattern consisting of three types of particles can be obtained by repeating the same process.

[0067] Next, a binder that can be peeled off from the attachment surface 21 is filled between the particles arranged on the attachment surface 21. For example, a processing liquid in which a binder is dissolved is filled into the particle pattern on the intermediate transfer body. This makes it possible to obtain a material layer that is an integrated body of particles and binder. The method for supplying the binder-containing treatment liquid is not limited, and any known method can be used. In the apparatus shown in Figure 3, an air knife coater 13 is used as a means for applying the treatment liquid. From the perspective of maintaining the particle layer with a smaller amount of binder, a "contour coater" application method is preferred, which applies excess treatment liquid on the particle layer by tracing the surface shape, as with an air knife coater. It is also preferable that the liquid can be drained without contact.

[0068] Since the particles on the intermediate transfer body are held in place by the adhesiveness of the surface of the intermediate transfer body, the particle pattern may be disrupted if a "flattening coater" that applies a strong shear, such as a blade or reverse roller, is used. When using these, it is preferable to control the properties of the treatment liquid (mainly viscosity) and the conditions for draining the liquid (relative speed, gap, etc.).

[0069] The binder is not particularly limited as long as it is a material that can hold the particles and be peeled off from the adhesive layer. The binder is preferably a resin material, more preferably a thermoplastic resin. Examples of the binder include at least one selected from the group consisting of acrylic resin, polyester resin, polyolefin resin, vinyl resin such as ethylene vinyl acetate, fluorine-based resin such as polyvinylidene fluoride, cellulose-based resin such as carboxymethyl cellulose, rubber-based resin such as styrene-butadiene copolymer rubber, and polyalkylene oxide resin. The binder may also be a material having ionic conductivity. Furthermore, it may be a thermosetting resin, a UV-curable resin, or a resin that can be cured by a two-component reaction. Among these, the binder includes at least one selected from the group consisting of acrylic resin and polyalkylene oxide resin. It is preferable that the resin contains a resin, and more preferable that the resin contains an acrylic resin.

[0070] The solvent in the binder-containing treatment liquid is not particularly limited, and may be selected from those that have low compatibility with the surface to be adhered to. Examples of the solvent include at least one selected from the group consisting of aqueous solvents such as water; alcoholic solvents such as methanol, ethanol, propanol, isopropyl alcohol, butanol, ethylene glycol, propylene glycol, and glycerin; and organic solvents such as N-methyl-2-pyrrolidone (NMP), methyl ethyl ketone (MEK), chloroform, and dimethyl sulfoxide (DMSO). The solvent is preferably at least one selected from the group consisting of N-methyl-2-pyrrolidone (NMP) and methyl ethyl ketone (MEK).

[0071] The concentration of the binder in the binder-containing treatment liquid is not particularly limited as long as it is within a range that allows the binder to be filled into the particles and form an integrated product. The amount of the binder in the binder-containing treatment liquid is preferably 1 to 50 mass %, 2 to 20 mass %, or 2 to 10 mass %. The amount of binder relative to the particles is, for example, 0.1 to 2.0, preferably 0.2 to 1.0, and more preferably 0.3 to 0.5, in terms of the volume ratio of binder to particle volume.

[0072] The device in Figure 3 uses N-methyl-2-pyrrolidone (NMP) as the solvent for the treatment liquid, a combination that has poor compatibility with the silicone rubber in the particle-carrying layer of the intermediate transfer body 1. At first glance, it might seem that the treatment liquid would be repelled by a surface with poor compatibility and that it would be impossible to apply a thin layer, but this is not a problem because the treatment liquid can penetrate into the gaps between the particles on the adhesion surface by capillary action. Therefore, if it is difficult to apply the treatment liquid to the adhesion surface, it is sufficient to make the particle surfaces lyophilic, rather than the adhesion surface.

[0073] The air knife coater 13 used in the device shown in Figure 3 is described with reference to Figure 4. The air knife coater 13 is configured with an air knife 41 positioned at an angle to the transport direction of the intermediate transfer body 1, and a binder liquid supply unit 42 located upstream. Binder liquid is continuously supplied from the binder liquid supply unit 42 located at the tip of the air knife 41, and the tilted air knife blows air across the width, spreading the liquid across the entire surface of the particles on the intermediate transfer body 1 (the liquid flow is conceptually indicated by arrows). The processing liquid that has traversed the intermediate transfer body is then collected by a binder liquid collection unit 43 located at the rear end of the air knife 41. In this device, the surface of the intermediate transfer body is made of silicone rubber, so binder liquid is repelled from areas where particles are not attached. This allows binder liquid to be applied only to areas where particles are attached, filling the spaces between the particles.

[0074] Generally, it is extremely difficult to form a thin layer film that is an integrated body of particles and binder in a peelable state. For example, when the treatment liquid and the attachment surface are combined in a way that they are compatible with each other, a thin layer film can be formed, but the peelability from the attachment surface, i.e., the transferability, may be reduced. Conversely, when the treatment liquid and the attachment surface are combined in a way that they are not compatible with each other, the transferability can be ensured, but the treatment liquid is repelled, making it difficult to form a thin layer. This is a fundamental phenomenon that generally occurs when applying a slurry liquid in which particles and a binder liquid are mixed in advance. To resolve this contradictory relationship, this disclosure uses a process in which the particles are first temporarily fixed to the application surface as a solid, and then the binder liquid is applied later.

[0075] To reiterate, this method is particularly suited to forming thin layers with high particle density. In other words, with the general slurry coating method mentioned above, creating a film with high particle density requires increasing the particle concentration in the slurry, which results in a high viscosity of the slurry. The higher the viscosity, the more difficult it becomes to apply a thin layer, especially on surfaces that are difficult to adhere to and tend to repel.

[0076] Although it is a binder liquid, there are no limitations on its use. Resin materials are preferred because they dissolve easily in solvents and the lower the viscosity of the solution, the easier it is to apply. As mentioned earlier, unlike a slurry liquid in which particles and binder liquid are premixed, it can be applied without containing particles, so it can be applied at a low viscosity, and there is no need for dispersion stabilization with the particles, so a wide variety of materials can be used depending on the purpose. The device in Figure 3 uses a thermoplastic acrylic binder that is easy to degrease and remove.

[0077] After the binder liquid is supplied, the solvent in the treatment liquid is removed as necessary to complete a material layer that is an integrated body of particles and binder. The device shown in Figure 3 is equipped with a mechanism for heating the back side of the intermediate transfer body 1 with a hot plate as a solvent removal promoting means 14. The thickness of the obtained material layer is not particularly limited, but is preferably 0.2 to 200 μm, more preferably 1 to 100 μm, even more preferably 2 to 50 μm, and even more preferably 5 to 20 μm.

[0078] Next, the resulting material layer is peeled from the attachment surface, and multiple material layers are stacked to obtain a stack of material layers. After peeling multiple material layers, the desired total number of material layers may be stacked to obtain a stack, or the stack may be obtained by repeatedly peeling and stacking material layers. In the apparatus of Figure 3, the stack is obtained by repeatedly peeling and stacking material layers. Here, when a material layer is to be obtained, the obtained material layer can be obtained by peeling it off from the attachment surface.

[0079] That is, a method for manufacturing a material layer according to one aspect of the present disclosure is a method for manufacturing a material layer, comprising: The manufacturing method includes: disposing a plurality of particles on an attachment surface of a first substrate having the attachment surface; a step of filling a binder releasable from the attachment surface between the plurality of particles arranged on the attachment surface to obtain a material layer that is an integral body of the particles and the binder; peeling the layer of material from the attachment surface; It has.

[0080] The means for peeling is not particularly limited, and a peeling roller or the like may be used, as with the mask 22, or any known means may be employed. In the present disclosure, the process for obtaining a laminate preferably includes a process of heating the material layer to bring the material layer into contact with a transfer target (transfer recipient), then cooling the material layer as needed to peel the material layer from the adhesive surface, and transferring the material layer to the transfer target. A laminate can be obtained by repeating the process of transferring the material layer to the transfer target. That is, the transfer target is the desired transfer material (e.g., a current collector) when the material layer is transferred for the first time, and the transfer target for the second or subsequent transfers is the material layer transferred in the previous process.

[0081] Although a material layer of particles and a binder, such as that of the present disclosure, is brittle and difficult to peel, the heating and cooling process described above allows for better peeling, transfer, and lamination even with less binder. The heating temperature of the material layer during transfer is not particularly limited as long as it is a temperature that can provide adhesion between the material layer and the transfer target, and examples thereof include 80 to 300°C and 130 to 200°C. The cooling temperature during peeling is not particularly limited as long as it allows the material layer and the adhesive surface to be peeled off. Examples include 25 to 180°C, 25 to 80°C, and 25 to 40°C. If peeling is possible without cooling, cooling is not necessary.

[0082] The apparatus 100 in Fig. 3 has a lamination device 15 for laminating material layers. In the apparatus in Fig. 3, the mask pattern is changed on demand, so that the particle pattern can be formed in the order of lamination of the design. Since the lamination device 15 has a rotation mechanism, it is possible to continuously laminate the patterns one after the other. In addition, the lamination device 15 has a rotation mechanism, so it is possible to laminate the patterns by changing the lamination angle. Depending on the shape and material of the pattern, the ease of forming the pattern may change depending on the conveyance direction, so it is possible to change the angle and position here to deal with this.

[0083] Since the binder can develop surface tackiness (plasticity) when heated, the device in Figure 3 has a heater 16 located below the intermediate transfer body, and the heater at a predetermined temperature can be moved up and down (contact and separation) to heat the material layer on the intermediate transfer body 1. Once the binder has been heated to a state where it can be laminated, the material layer is brought into pressure contact with the object to be transferred (for example, aluminum foil that will become the current collector of a battery).

[0084] On the other hand, it is preferable to cool the material layer after contacting the material layer with the transfer target. Cooling tends to reduce the adhesion between the intermediate transfer body and the material layer. It is preferable to cool from the adhesion surface side of the material layer. In order to ensure reliable transfer, the device in Figure 3 is equipped with a mechanism that lowers the heater after pressure contact and blows air with a cooling fan 17 to lower the temperature of the intermediate transfer body. As the temperature decreases, the adhesiveness of the thermoplastic resin in the material layer decreases, and then the lamination device is raised to complete the transfer. This is repeated a predetermined number of times to complete the laminate of material layers.

[0085] 3, the lamination device 15 repeatedly contacts (preferably pressurized contact) and peels off the material layer conveyed by the intermediate transfer body 1 at predetermined intervals to repeatedly transfer the material layer and obtain a laminate. In the transfer process, it is preferable to repeatedly heat the material layer, bring the material layer into contact with the transfer target, cool the material layer, and peel it off. If the binder resin is a curable resin such as a thermosetting resin, a UV-curable resin, or a two-component curable resin, lamination and curing may be performed simultaneously in the process of obtaining the laminate. For example, in the case of a thermosetting resin, the binder resin can be cured by heating the material layer.

[0086] The lamination process is not limited to this example, and for example, the same pattern may be created multiple times for a certain number of sheets, and the patterns may be selected and laminated one after another later. The configuration of the device is not limited to the flat plate pressure welding type as shown in FIG. 3, but may be a belt type rotary type or a roller type.

[0087] The surface of the transferred material layer, i.e., the surface that was in contact with the intermediate transfer body, has a characteristic shape, meaning that at least some of the particles that were sunk into the intermediate transfer body and held thereon are not covered with the binder and the particle surfaces are exposed. In the slurry method, a typical conventional coating production method, functional particles are mixed with a binder and solvent beforehand, so almost all of the particle surface is covered with the binder at the time of slurry production. If even a portion of the functional particle surface is exposed, it can be directly contacted with the surface to be transferred. For example, when creating a three-dimensional wiring pattern using metal particles, the contact point can be secured, resulting in low resistance, and in the case of a heat dissipation device, the thermal conductivity can be improved, making it a feature that can be widely applied to a variety of uses.

[0088] Therefore, a material layer according to one embodiment of the present disclosure is a material layer that is an integral body of a plurality of particles and a binder, the binder is filled between the particles, At least a portion of the particles is exposed from the binder on at least one surface of the material layer; When the material layer is observed from the side where at least a part of the plurality of particles is exposed, the particle size distribution of the particles is determined based on the area of ​​a particle arrangement area where the plurality of particles are present. The ratio of the total area of ​​the covered portions (hereinafter also referred to as the area ratio of the exposed portions) is 1 to 70 area %.

[0089] The area ratio of the exposed portions is preferably 5 to 70 area%, more preferably 10 to 70 area%, and even more preferably 20 to 60 area%. An area ratio of 1 to 70 area% of the exposed portions can be achieved by the above-mentioned method for manufacturing the material layer. For example, in the case of a material layer obtained by mixing particles and a binder resin and applying the mixture, the exposed portions will not appear, and the area ratio of the exposed portions will be 0 area%.

[0090] 6A is a schematic diagram of a material layer observed from the side where the particles are exposed. The particle arrangement area 200 to be observed is indicated by a square. Multiple particles 201 are buried, and particle exposed portions 210 are formed where the particles 201 are exposed from the binder 27. The particle buried portions 220 where the particles are buried are indicated by dotted lines. The area ratio of the exposed portions is the ratio of the total area of ​​the particle exposed portions 210 to the area of ​​the particle arrangement area 200. It is preferable that at least a portion of the particles is exposed from the binder on one surface of the material layer. Figure 6B is a cross-sectional view of the material layer in the thickness direction. As described above, particles 201 are exposed from one surface of the material layer.

[0091] The arrangement pitch 230 of the particle exposed portions 210 is preferably 25 to 400% of the particle diameter, and more preferably 50 to 200%. The arrangement pitch 230 of the particle exposed portions 210 is measured as follows. In the particle arrangement area 200, a line is drawn that passes through the geometric centers of multiple particle exposed portions 210. In Fig. 6A, this line is represented by a dashed line. For example, a field angle is set that allows several tens of particles or more to be observed, and the distance between the geometric centers of adjacent particle exposed portions is the arrangement pitch 230 of the particle exposed portions. It is preferable that the average distance of the arrangement pitch falls within the above range.

[0092] Furthermore, the appearance probability (appearance rate), which is the proportion of particles that form particle exposed portions among the particles included in the particle arrangement area 200, is preferably 40 to 100% by number, more preferably 70 to 100% by number, and even more preferably 90 to 100% by number.

[0093] Such an arrangement pitch and probability of appearance of exposed portions can be achieved by the above-described method for manufacturing the material layer. For example, it is considered difficult to achieve such an arrangement pitch and probability of appearance of exposed portions by a conventional method, such as a material layer obtained by mixing particles and a binder resin and applying the mixture.

[0094] The area ratio of exposed parts, the arrangement pitch of exposed particle parts, and the probability of appearance of exposed parts can be obtained from information obtained by mapping the surface composition using X-ray photoelectron spectroscopy (XPS). The specific procedure is as follows. Mapping is performed by specifying the binder or components specific to the particle material. Specifically, if an acrylic binder is used as the binder resin for LCO particles, exposed LCO areas can be confirmed in a Co (cobalt) mapping image. In a normal secondary electron image, exposed LCO areas appear white due to differences in the conductive properties of the material, and binder components appear black. The observation area should be approximately 5 to 10 times square the average particle diameter of the particles used. The observed image is binarized with a threshold of 80 and then processed. The area ratio of exposed LCO areas can be determined from the number of white pixels divided by the total number of pixels, the arrangement pitch from the coordinate values ​​of the geometric center of the exposed particle areas of each particle, and the occurrence probability from the rate at which striped areas are detected at the specified arrangement pitch. In Figure 6, the particles are shown as spherical in model form, but in reality, the image often looks like Figure 7, for example.

[0095] The material layer is as described in the above-mentioned manufacturing method, and the plurality of particles preferably includes first particles and second particles. The plurality of particles may be a plurality of particles of a single material, for example, a plurality of first particles. The material layer according to one embodiment of the present disclosure may be a material layer obtained by the manufacturing method of a material layer laminate according to one embodiment of the present disclosure. At least a portion of the particles may be exposed from the binder on both surfaces of the material layer, or at least a portion of the particles may be exposed from the binder on one surface of the material layer, i.e., at least one surface of the material layer has a surface made of the binder and the particles exposed from the binder.

[0096] Although the material layer is an integrated body of particles and a binder, the embodiment of the material layer is not limited thereto, and the material layer may include other layers. For example, the present disclosure provides a laminate in which the material layer is held on an intermediate transfer body. The laminate may also be a laminate in which multiple material layers are stacked on an intermediate transfer body. In these laminates, the particle-exposed portion may be in contact with the intermediate transfer body, or the particle-exposed portion may form the outer surface of the laminate. Such a laminate embodiment allows the material layer to be transferred to a desired transfer target to form a desired particle structure.

[0097] The present disclosure also provides a laminate in which a material layer is supported on a current collector or a solid electrolyte. The laminate may also be a laminate in which multiple material layers are stacked on a current collector or a solid electrolyte. The particle-exposed portion may be in contact with the current collector or the solid electrolyte, or may form the outer surface of the laminate. In such an embodiment, the desired electrode material can be formed by degreasing the binder in the material layer. The material layer may be a single material layer or a laminate of multiple material layers.

[0098] The production apparatus of Figure 3 can produce a substantially single-layer particle pattern. Furthermore, this substantially single-layer particle pattern can be stacked to form a laminate. Figure 5A shows an example of a laminate. Then, binder 27 can be removed from laminate 401 to obtain particle laminate 402 (three-dimensional object 402) (Figure 5B). On the other hand, Figure 5C shows a conventional laminate 501 in which particles arranged on a substrate are laminated in a conventional manner. Because conventional laminate 501 has a large amount of substrate, it takes a lot of time and effort to remove the substrate from laminate 501 to obtain particle laminate 502 (Figure 5D). For example, removing the substrate by heating requires a lot of heat.

[0099] Compared to the conventional laminate 501, the laminate 401 according to the present disclosure has less base material and can obtain a particle laminate with less energy. The number of layers in the laminate is not particularly limited and can be changed depending on the purpose of the laminate.

[0100] In addition, in the present disclosure, three-dimensional object 402 may be manufactured by removing binder 27 from laminate 401 and molding a three-dimensional object containing particles. The method for removing the binder is not particularly limited, but for example, a patterned laminate made of particles can be obtained by degreasing the laminate at high temperature. Therefore, the manufacturing method of the laminate preferably includes a step of heating the laminate to remove the binder.

[0101] When finally removing the binder, a highly removable material should be selected depending on the removal method. The removal method should be selected depending on the characteristics of the particles used. For example, one method is to dissolve and remove the binder using a solvent, but the conditions should be selected so that the fluidity of the liquid does not disrupt the pattern. Another method is to use a photodegradable photosensitive material, but the light rays may be blocked by the particles depending on the particle material, so the conditions must be selected accordingly. If the particle material is resistant to high temperatures, removal by heating can be selected. This method can be reproduced relatively easily by selecting the binder material. As mentioned above, an example is a method in which an acrylic resin is used as a binder.

[0102] The conditions for high-temperature degreasing are not particularly limited, but it is preferable to heat the laminate at a temperature equal to or higher than the thermal decomposition temperature of the binder and lower than the thermal decomposition temperature of each particle layer in the laminate. In the present disclosure, the temperature and time can be set lower than those in conventional high-temperature degreasing of laminates. The temperature to which the laminate is heated is preferably 200°C or higher and 1000°C or lower, more preferably 300°C or higher and 600°C or lower, particularly preferably 300°C or higher and 500°C or lower, and even more preferably 300°C or higher and 400°C or lower.

[0103] It is preferable to maintain the sintering temperature for 10 minutes or more, and more preferably for 20 minutes or more. There is no particular upper limit, but it may be, for example, 3 hours or less, 1 hour or less, or 40 minutes or less. For example, it is preferable to maintain the sintering temperature for 10 minutes to 3 hours, 20 minutes to 1 hour, or 20 to 40 minutes.

[0104] The thermal decomposition temperature is the temperature at which the weight of a material begins to decrease when the temperature is gradually increased in a heating atmosphere in a sintering treatment device. Therefore, by heating the laminate at a temperature equal to or higher than the thermal decomposition temperature of the binder, the binder in the laminate can be decomposed, reducing its weight and removing the binder from the laminate.

[0105] In the present disclosure, by selecting a specific resin material as the binder, the time required for the degreasing process can be shortened. Shortening the degreasing process not only improves production efficiency but also reduces the thermal load on the material particles, thereby suppressing, for example, deterioration of the material particles. If the heating rate is set high, for example at 10°C / min, in an attempt to shorten the debinding time, the properties and yield rate may decline in some cases. This is thought to be because decomposition proceeds rapidly within a narrow temperature range of the thermal decomposition temperature range, and if a large amount of decomposition gas is generated in a short period of time, the particle arrangement arranged during film formation is disrupted. In response to this, rapid temperature rise can be accommodated by selecting a resin as the binder that begins to decompose at low temperatures. A suitable resin selection criterion is one that has a large weight loss rate below 300°C. For example, when a resin material is subjected to thermogravimetry (TG) at a temperature rise rate of 10°C / min, the weight loss rate from 100°C to 300°C calculated by the following formula should be 40.0% by weight or more, preferably 50.0% by weight or more, more preferably 60.0% by weight or more, and particularly preferably 70.0% by weight or more. Weight loss rate from 100 to 300°C = ((remaining weight at 100°C - remaining weight at 300°C) / (remaining weight at the start of measurement - remaining weight at 1000°C)) x 100

[0106] The upper limit of the weight loss rate at 100 to 300°C is not particularly limited, but the weight loss rate at 100 to 300°C may be 40.0 to 99.0 wt%, 50.0 to 99.0 wt%, 60.0 to 99.0 wt%, or 70 to 99.0 wt%. By selecting a resin that satisfies the above conditions as a binder, degreasing can be performed without rapid decomposition. The reason for not including temperatures below 100°C as an index is to eliminate the influence of water evaporation. The thermogravimetric measuring instrument used should conform to JIS K0129. In addition, it is preferable that the measurement atmosphere be the same as the actual degreasing atmosphere. The weight loss rate at 100 to 300°C can be controlled by the resin used.

[0107] This disclosure can be widely applied to functional materials, but one area in which it is particularly suitable is battery modules. Battery materials are expected to achieve higher performance by functionally arranging the materials in the electrode layers and efficiently arranging paths for ions and electrons. In particular, all-solid-state batteries do not use electrolytes, so this disclosure makes it possible to functionally arrange positive and negative electrode materials, solid electrolyte materials, etc. according to an optimized pattern. Cut.

[0108] The first particles are not particularly limited, and desired resin particles, inorganic particles, etc. can be used. Examples of resin particles include (meth)acrylic resin particles, urethane resin particles, and ester resin particles. Metal particles such as copper particles may also be used. When the method for producing a material layer according to the present disclosure is used as a method for producing a precursor for a solid-state battery, it is preferable that the first particles contain at least one of active material particles and solid electrolyte particles, for example.

[0109] The active material particles are not particularly limited, and known active material particles can be used. For example, lithium-containing composite oxides can be used. Specific examples include Li-Co oxide active material particles such as LiCoO2 (lithium cobalt oxide), LiMO2 (where M is an element selected from the group consisting of Ni, Mn, and Co), Li-PO4 oxide active material particles, lithium vanadium compounds (Li3V2(PO4)3, LiVOPO4), and olivine-type phosphate compounds (LiMPO4 (where M is one or more elements selected from the group consisting of Co, Ni, Mn, Fe, Mg, V, Nb, Ti, Al, and Zr)). Active material particles that do not contain lithium can also be used. Specific examples include metal oxides (MnO2, V2O5, etc.) and fluorides (FeF3, VF3, etc.). Among these, it is preferable to include Li-Co oxide-based active material particles and Li-PO4 oxide-based active material particles. Furthermore, negative electrode active material particles such as graphite, Si, and lithium titanate (LTO) can also be used.

[0110] The solid electrolyte is not particularly limited, and known solid electrolytes can be used. Examples include Li-B oxide-based solid electrolyte particles such as lithium borate, Li-Yb oxide-based solid electrolyte particles, Nasicon-type solid electrolyte particles (LiAlTi(PO4)3, LiAlGe(PO4)3, etc.), and Li-PO-based solid electrolyte particles (Li3PO4, LiPON (particles in which part of the O in Li3PO4 is replaced with N), etc.). Among the above solid electrolyte particles, it is preferable to use Li-B oxide-based solid electrolyte particles and Li-Yb oxide-based solid electrolyte particles.

[0111] The second particles are not particularly limited, and as with the first particles, desired resin particles, inorganic particles, etc. can be used. When the method for manufacturing a material layer of the present disclosure is used as a method for manufacturing a precursor for a solid-state battery, the second particles preferably include, for example, at least one of active material particles and solid electrolyte particles. Specifically, the active material particles and solid electrolyte particles described above as the first particles can be used.

[0112] The first particles and the second particles may each be of one type, or a combination of multiple types. When multiple types are combined, multiple types of particles may be premixed in advance. The particle surfaces may be subjected to a surface treatment or coating.

[0113] The method for manufacturing a stack of material layers according to the present disclosure can be used as a method for manufacturing a precursor for a solid-state battery, that is, the stack of material layers is preferably a precursor for a solid-state battery.

[0114] When the method for manufacturing a laminate of material layers according to the present disclosure is used as a method for manufacturing a precursor for a solid-state battery, it is preferable that the first particles include at least one of active material particles and solid electrolyte particles, and the second particles include at least one of active material particles and solid electrolyte particles. More preferably, the first particles include at least one of active material particles and solid electrolyte particles, and the second particles include the other of active material particles and solid electrolyte particles. Even more preferably, the first particles include active material particles, and the second particles include solid electrolyte particles.

[0115] Furthermore, an anisotropic conductive material layer can be obtained by using at least one of metal particles and resin particles as the first particles and the other of metal particles and resin particles as the second particles.

[0116] The precursor of the solid-state battery may be, for example, a material layer of the solid-state battery. The precursor of the solid-state battery is preferably a material layer of an electrode of the solid-state battery. Therefore, the method for producing an electrode of the solid-state battery includes a step of heating and degreasing the laminate obtained by the above-mentioned production method to remove the binder and obtain an electrode.

[0117] That is, an electrode for a solid-state battery can be obtained by removing the binder from the laminate and forming a three-dimensional object containing the particles. The above-mentioned processes can be used for the process of obtaining the laminate and the process of forming the three-dimensional object. The electrode may be a positive electrode or a negative electrode. The number of layers in the laminate is not particularly limited and can be changed depending on the purpose of the electrode to be manufactured. For example, three or more layers can be used. [Example]

[0118] The present disclosure will be specifically described below with reference to examples, but these examples are not intended to limit the present disclosure in any way. In the following formulations, parts are by mass unless otherwise specified.

[0119] Example 1 An example of producing a positive electrode material layer (single material particles) for an all-solid-state battery using the production apparatus shown in Figure 3 will be shown. The particles used were cobalt lithium (Nippon Chemical Industry Co., Ltd.: volumetric median diameter D50: 5 μm) as a positive electrode material. The intermediate transfer belt used consisted of a 0.1 mm thick polyamide film support and a 45 μm thick silicone rubber (KE44 manufactured by Shin-Etsu Chemical Co., Ltd.) coating as a particle-carrying layer with an adhesive surface. The adhesive surface had a rubber hardness of 30° and a surface adhesive force of 0.25 mN / 20 mm. Magnetic particles (P02 manufactured by the Imaging Society of Japan) were used in particle supply units 7 and 11. The binder liquid was acrylic resin (Kyoeisha Chemical: Oricox KC-1300: 5 mass% NMP solution). The fabrication apparatus shown in FIG. 3 was used to fabricate the above-described steps to fabricate a positive electrode material layer (film thickness 5.5 μm) for an all-solid-state battery. The resulting positive electrode material layer was observed using an electron microscope (Hitachi High-Technologies Corporation: S-4800) at an accelerating voltage of 15 kV and a magnification of 3000x (field of view approximately 400 μm x 300 μm), obtaining a secondary electron image of 200 x 256 pixels. Elemental mapping of Co (cobalt) was performed using an EDX analyzer (EDAX Corporation: Genesis 2000) in the same observation field, and exposed LCO particles were confirmed by the high detection amount in the white islands in the image. The obtained secondary electron image was binarized with a threshold of 80 and the ratio of white pixels was calculated. The area ratio of exposed LCO particles was 56.6 area%, the arrangement pitch of exposed particles was 65 to 122% of the particle diameter, and the occurrence probability of exposed particles was 91 number %.

[0120] Example 2 An example of producing a positive electrode material layer for an all-solid-state battery using the production device shown in Figure 3 is shown below. The first particles were made of a positive electrode material: lithium cobalt oxide (Nippon Chemical Industry Co., Ltd.: volumetric median diameter D50: 5 μm), and the second particles were made of a solid electrolyte: lithium borate (Toshima Manufacturing Co., Ltd.: volumetric median diameter D50: 5 μm). The intermediate transfer belt was made of a 0.1 mm thick Invar support with an 80 μm thick silicone rubber (Dow Toray Industries: SE9186) coated on the support as a particle-carrying layer. The adhesive surface had a rubber hardness of 20° and a surface adhesion of 0.5 mN / 20 mm. In addition, a polyester film (thickness 1.5 μm, Mitsubishi Chemical: K91) was used as a masking layer. 7) was used, and a UV laser processing machine (Kokyo: fine UV laser marker) was used to create the mask openings. Magnetic particles (Japan Imaging Society: P02) were used for particle supply units 7 and 11. In addition, acrylic resin (Kyoeisha Chemical: Oricox KC-1700: 5 mass% NMP solution) was used as the binder liquid. Then, using the production apparatus shown in Figure 3, each of the above-mentioned steps was carried out to produce a positive electrode material layer (film thickness 5.5 μm) for an all-solid-state battery. The mask openings were a 10 μm stripe pattern with lines and spaces, i.e., the openings were striped with a width of 10 μm. Observation of the resulting positive electrode layer revealed that the area ratio of the exposed portions was 17 area %, the arrangement pitch of the exposed particle portions was 60 to 131% of the particle diameter, and the appearance probability of the exposed portions was 94 number %.

[0121] Then, following the production of the positive electrode material layer, the positive electrode material layer was peeled off and laminated using the lamination device 15 in the apparatus of Fig. 3. Specifically, three layers were laminated on an aluminum foil (20 μm thick) while shifting the lamination angle by 90 degrees (pressure welding temperature 190°C, peeling temperature 140°C) to obtain a laminate. The obtained laminate was degreased by heating at 350°C for 0.5 hours in an electric furnace (MMF-1 manufactured by AS ONE Corporation) to remove the binder, and a positive electrode material layer laminate (thickness: 15 μm) for an all-solid-state battery was produced.

[0122] This positive electrode material laminate was used to prepare a prototype battery under the following conditions. A sintered body was obtained by processing and molding the solid electrolyte LAGP (Toshima Manufacturing Co., Ltd.) to a thickness of 250 μm and then sintering it at 850°C. On both sides of the sintered body, the fabricated positive electrode material laminate and 50 μm thick indium metal foil as the negative electrode material were layered, and each was connected to an extraction electrode, vacuum-packed with an aluminum laminate sheet, and finally pressurized at 200 MPa in a CIP device to obtain a prototype battery. The prototype battery was able to be charged and discharged normally, and the charge capacity when charged and discharged at a charge / discharge rate of 0.1C was 86% of the theoretical value (measured using an electrochemical device (Solartron 1255WB model)).

[0123] (Comparative Example 1) As in Example 2, a pattern consisting of the first particles and the second particles was formed on the intermediate transfer body (the state shown in FIG. 2E), and this pattern was transferred to a double-sided tape (Nitto Denko: No. 5600) as a substrate without using a binder liquid to form a positive electrode material layer (film thickness 9.2 μm) for an all-solid-state battery. Three layers of the prepared positive electrode material layer were laminated on aluminum foil (20 μm thick) with a 90° offset (pressing temperature: room temperature) to obtain a laminate. The obtained laminate was heated and degreased at 350 °C for 0.5 hours in an electric furnace (MMF-1 manufactured by AS ONE Corporation), and the double-sided tape substrate was removed to obtain a positive electrode material layer laminate (thickness: 15 μm) for an all-solid-state battery. The battery characteristics were measured in the same manner as in Example 2, but the prototype battery had high resistance and did not function as a battery. After the start of the measurement, the cutoff setting (3.6 V) was exceeded soon after the measurement started, so the measurement was stopped.

[0124] Example 3 The positive electrode material layer (single layer) prepared in Example 2 was degreased at 350° C. for 0.5 hours, and the remaining amount of binder was evaluated from the mass ratio before and after degreasing. (The mass raw material ratio of particles only under the same degreasing conditions was measured separately, and the value was corrected for the weight loss due to particles.) As a result, the amount of binder remaining after degreasing was 0.80% by mass, which indicated a good degreasing state.

[0125] (Comparative Example 2) The positive electrode material layer (single layer) produced in Comparative Example 1 was degreased at 350°C for 0.5 hours, and the remaining amount of binder was evaluated from the mass ratio before and after degreasing. As a result, the remaining amount of binder was 96.04 mass%, meaning that almost no binder had been removed.

[0126] (Comparative Example 3) The positive electrode layer (single layer) produced in Comparative Example 1 was degreased at 450°C for 0.5 hours, and the binder amount was evaluated from the weight ratio before and after degreasing. As a result, the remaining binder amount was 16.92 mass%, indicating insufficient removal.

[0127] Comparative Example 4 The positive electrode layer (single layer) produced in Comparative Example 1 was degreased at 500°C for 0.5 hours, and the remaining amount of binder was evaluated from the weight ratio before and after degreasing. As a result, the remaining amount of binder was 12.88 mass%, which meant that removal was still insufficient.

[0128] (Comparative Example 5) The positive electrode material layer (single layer) prepared in Comparative Example 1 was degreased at 500°C for 1 hour, and the binder amount was evaluated from the weight ratio before and after degreasing. As a result, the remaining binder amount was 0.77 mass%, and the degreasing conditions for obtaining a value similar to that of Example 3 were identified, and heating at a high temperature for a long time was required.

[0129] Comparison of degreasing conditions and residual binder amounts in Example 3 and Comparative Examples 2 to 5 [Table 1]

[0130] Example 4 A positive electrode material layer (film thickness 5.5 μm) for an all-solid-state battery was fabricated in the same manner as in Example 2, except that an acrylic resin (Kyoeisha Chemical: Oricox KC-1700 5 mass% MEK solution) was used as the binder solution. The mask openings were in a 10 μm stripe pattern with lines and spaces. Observation of the resulting positive electrode material layer revealed that the area ratio of exposed portions was 46.6 area %, the arrangement pitch of exposed particle portions was 57 to 137% of the particle diameter, and the occurrence probability of exposed portions was 84% ​​by number.

[0131] Then, following the production of the positive electrode material layer, the positive electrode material layer was peeled off and laminated using lamination device 15 in the apparatus of Fig. 3. Specifically, three layers were laminated on an aluminum foil (20 µm thick) while shifting the lamination angle by 90 degrees (pressure welding temperature 190°C, peeling temperature 140°C) to obtain a laminate. After peeling and transfer of the laminate were completed, the transfer rate of the material layer was measured. Transfer rate=((mass of intermediate transfer body with material layer attached−mass of intermediate transfer body after material layer transfer) / (mass of intermediate transfer body with material layer attached−initial mass of intermediate transfer body))×100 As a result, the average transfer rate of the three layers was 99.4% by mass, which was a good value. There was no discomfort.

[0132] Example 5 An example of producing an anisotropic conductive rubber laminate using the apparatus of FIG. 3 will be described. The first particles were copper particles (in-house prototype: granulated by disk atomization and then sieved, volumetric median diameter D50: 30 μm), and the second particles were elastic particles: cross-linked polyacrylic ester (Sekisui Chemical Co., Ltd.: ARX-30, volumetric median diameter D50: 30 μm). The intermediate transfer belt used consisted of a 0.1 mm thick Invar support and an 80 μm thick silicone rubber (Dow Toray: SE9186) coating as a particle-carrying layer with an adhesive surface. The adhesive surface had a rubber hardness of 20° and a surface adhesion of 0.5 mN / 20 mm. Furthermore, SUS430 (30 μm thick) was used as the mask layer, and a UV laser processing machine (Kokyo: fine UV laser marker) was used to create the mask openings. Furthermore, a forward-rotating roller unit with a urethane rubber roller (rubber hardness 70 degrees) was used as the particle supply unit. Acrylic resin (Kyoeisha Chemical: Oricox KC-7000F 10 mass% NMP solution) was used as the binder liquid. Then, using the device shown in Figure 3, the above-mentioned steps were carried out to create an anisotropic conductive rubber laminate. The mask openings were in a 100 μm stripe pattern with lines and spaces. Furthermore, when the obtained material layer was observed, the area ratio of the exposed portions was 34.1 area %, the arrangement pitch of the particle exposed portions was 43 to 167% of the particle diameter, and the appearance probability of the exposed portions was 71% by number.

[0133] In addition, a magnet was placed on the backside of the intermediate transfer body to hold the mask in place using magnetic force from the mask application process to the mask peeling process.The anisotropically conductive rubber material laminate obtained by stacking 20 of the anisotropically conductive rubber material layers in the same lamination direction was able to be manufactured with stable quality as an anisotropically conductive rubber laminate with low resistance in the stripe direction.

[0134] (Examples 6 to 10, Reference Examples 6 to 8) Batteries were fabricated under the same conditions as in Example 2, except that the degreasing conditions were 500°C for 1 hour, the heating rate was 20°C / min, and the binder resin was changed to one listed in Table 2. The results are shown in Table 2. The yield was calculated by judging that no 0.1C charge / discharge was observed as a failure. Examples using resins with a weight loss rate of more than 60.0% by weight between 100 and 300°C had a high yield. The weight loss rate between 100 and 300°C was calculated by measuring the weight loss of each resin up to 1000°C at a heating rate of 10°C / min using a simultaneous differential thermal and thermogravimetric analyzer (STA200RV, manufactured by Hitachi High-Technologies Corporation). The weight at the start of the measurement (100°C) was set as the weight remaining at 100°C, and the weight remaining at 1000°C was set as 0, and the weight remaining at 100°C and 300°C was substituted into the following formula: Weight loss rate from 100 to 300°C = ((remaining weight at 100°C - remaining weight at 300°C) / (remaining weight at the start of measurement - remaining weight at 1000°C)) x 100 [Table 2]

[0135] The present disclosure relates to methods and compositions for: (Method 1) 1. A method for manufacturing a stack of material layers, comprising: The manufacturing method includes: disposing a plurality of particles on an attachment surface of a first substrate having the attachment surface; a step of filling a binder releasable from the attachment surface between the plurality of particles arranged on the attachment surface to obtain a material layer that is an integral body of the particles and the binder; peeling the material layer from the attachment surface to stack a plurality of the material layers to obtain a stack of the material layers; 4. A method for manufacturing a laminate of material layers, comprising: (Method 2) disposing a plurality of particles on the attachment surface; a first step of forming a mask on the attachment surface; a second step of disposing first particles on the attachment surface in the non-mask-formed portion; a third step of removing the mask from the deposition surface; a fourth step of disposing second particles in the non-disposed areas of the first particles remaining on the attachment surface; A method for producing a stack of material layers according to method 1, comprising: (Method 3) the first particles include at least one of active material particles and solid electrolyte particles, The method for producing a laminate of material layers according to Method 2, wherein the second particles include at least one of active material particles and solid electrolyte particles. (Method 4) 4. The method for producing a laminate of material layers according to any one of Methods 1 to 3, wherein the adhesive strength of the adhesive surface measured by a peel analysis device is 0.2 to 10 mN / 20 mm. (Method 5) the first substrate has a support and a particle-carrying layer laminated on the support to form the attachment surface, 5. The method for producing a laminate of material layers according to any one of methods 1 to 4, wherein the particle-supporting layer contains at least one selected from the group consisting of silicone rubber, urethane rubber, and fluororubber. (Method 6) The method for producing a laminate of material layers according to Method 5, wherein the particle-supporting layer contains 10 to 100% by mass of the silicone rubber. (Method 7) 7. The method for producing a laminate of material layers according to any one of Methods 1 to 6, wherein the rubber hardness of the adhesion surface measured in accordance with JIS K6253-3:2012 is 10° to 80°. (Method 8) The method for producing a laminate of material layers according to any one of Methods 1 to 7, wherein the step of obtaining the laminate includes the steps of heating the material layer to bring the material layer into contact with a transfer target, cooling the material layer to separate the material layer from the adhesive surface, and transferring the material layer to the transfer target (Method 9). 9. A method for producing a laminate of material layers according to any one of Methods 1 to 8, further comprising the step of heating the laminate to remove the binder. (Method 10) The method for producing a stack of material layers according to Method 3, wherein the stack of material layers is a precursor of a solid-state battery. (Method 11) A method for manufacturing an electrode for a solid-state battery, comprising: The manufacturing method comprises: A method for manufacturing an electrode for a solid-state battery, comprising: a step of heating and degreasing the laminate obtained by the method for manufacturing a laminate of material layers according to Method 3 to remove the binder, thereby obtaining the electrode. (Configuration 12) A material layer that is an integral body of a plurality of particles and a binder, the binder is filled between the particles, At least a portion of the particles is exposed from the binder on at least one surface of the material layer; A material layer characterized in that, when the material layer is observed from the side where at least a portion of the plurality of particles are exposed, the ratio of the total area of ​​the exposed portions of the particles to the area of ​​a particle arrangement area where the plurality of particles are present is 1 to 70 area %. (Configuration 13) the plurality of particles includes first particles and second particles; the first particles include at least one of active material particles and solid electrolyte particles, 13. The material layer of claim 12, wherein the second particles include at least one of active material particles and solid electrolyte particles. (Configuration 14) the binder is a resin material, The material layer according to aspect 13 or 14, wherein when the resin material is subjected to thermogravimetry at a temperature increase rate of 10°C / min, the weight loss rate at 100 to 300°C calculated by the following formula is 40% by weight or more relative to the remaining weight at 100°C. Weight loss rate from 100 to 300°C = ((remaining weight at 100°C - remaining weight at 300°C) / (remaining weight at the start of measurement - remaining weight at 1000°C)) x 100 (Method 15) 1. A method for manufacturing a material layer, comprising: The manufacturing method includes: disposing a plurality of particles on an attachment surface of a first substrate having the attachment surface; a step of filling a binder releasable from the attachment surface between the plurality of particles arranged on the attachment surface to obtain a material layer that is an integral body of the particles and the binder; peeling the layer of material from the attachment surface; 10. A method for manufacturing a material layer, comprising:

Claims

1. 1. A method for manufacturing a stack of material layers, comprising: The manufacturing method includes: disposing a plurality of particles on an attachment surface of a first substrate having the attachment surface; a step of filling a binder releasable from the attachment surface between the plurality of particles arranged on the attachment surface to obtain a material layer that is an integral body of the particles and the binder; peeling the material layer from the attachment surface to stack a plurality of the material layers to obtain a stack of the material layers; 4. A method for manufacturing a laminate of material layers, comprising:

2. disposing a plurality of particles on the attachment surface; a first step of forming a mask on the attachment surface; a second step of disposing first particles on the attachment surface in the non-mask-formed portion; a third step of removing the mask from the deposition surface; a fourth step of disposing second particles in the non-disposed areas of the first particles remaining on the attachment surface; A method for manufacturing a stack of material layers according to claim 1, comprising:

3. the first particles include at least one of active material particles and solid electrolyte particles, The method for manufacturing a stack of material layers according to claim 2 , wherein the second particles include at least one of active material particles and solid electrolyte particles.

4. The method for manufacturing a laminate of material layers according to claim 1, wherein the adhesive strength of the adhesive surface measured by a peel analysis device is 0.2 to 10 mN / 20 mm.

5. the first substrate has a support and a particle-carrying layer laminated on the support to form the attachment surface, The method for manufacturing a laminate of material layers according to claim 1 , wherein the particle-carrying layer contains at least one selected from the group consisting of silicone rubber, urethane rubber, and fluororubber.

6. The method for manufacturing a laminate of material layers according to claim 5 , wherein the particle-carrying layer contains 10 to 100% by mass of the silicone rubber.

7. The method for manufacturing a laminate of material layers according to claim 1, wherein the adhesive surface has a rubber hardness of 10° to 80° as measured in accordance with JIS K6253-3:2012.

8. 2. The method for manufacturing a laminate of material layers according to claim 1, wherein the step of obtaining the laminate includes the steps of heating the material layer to bring the material layer into contact with a transfer target, cooling the material layer to separate the material layer from the adhesive surface, and transferring the material layer to the transfer target.

9. The method for manufacturing a laminate of material layers according to any one of claims 1 to 8, further comprising the step of heating the laminate to remove the binder.

10. The method for manufacturing a stack of material layers according to claim 3 , wherein the stack of material layers is a precursor of a solid-state battery.

11. A method for manufacturing an electrode for a solid-state battery, comprising: The manufacturing method comprises: The laminate obtained by the method for manufacturing a laminate of material layers according to claim 3 is heated and degreased to form a pre-form. and removing the binder to obtain the electrode.

12. A material layer that is an integral body of a plurality of particles and a binder, the binder is filled between the particles, At least a portion of the particles is exposed from the binder on at least one surface of the material layer; A material layer characterized in that, when the material layer is observed from the side where at least a portion of the plurality of particles are exposed, the ratio of the total area of ​​the exposed portions of the particles to the area of ​​the particle arrangement area where the plurality of particles are present is 1 to 70 area %.

13. the plurality of particles includes first particles and second particles; the first particles include at least one of active material particles and solid electrolyte particles, The material layer according to claim 12 , wherein the second particles include at least one of active material particles and solid electrolyte particles.

14. the binder is a resin material, 15. The material layer according to claim 13, wherein when the resin material is subjected to thermogravimetry under a temperature increase condition of 10°C / min, the weight loss rate at 100 to 300°C calculated by the following formula is 40.0% by weight or more. Weight loss rate from 100 to 300°C = ((remaining weight at 100°C - remaining weight at 300°C) / (remaining weight at the start of measurement - remaining weight at 1000°C)) x 100

15. 1. A method for manufacturing a material layer, comprising: The manufacturing method includes: disposing a plurality of particles on an attachment surface of a first substrate having the attachment surface; a step of filling a binder releasable from the attachment surface between the plurality of particles arranged on the attachment surface to obtain a material layer that is an integral body of the particles and the binder; peeling the layer of material from the attachment surface; 10. A method for manufacturing a material layer, comprising:

Images